Electric hammer and drill



1,63'6'923 July 1927' N. PISCIONERE ELECTRIC HAMMER AND mum.

Filed March 12. 1925 2 sheets-she'i ,1

g-wwmtoo swa J 1927 N. PISCIONERE nuscmlc HAMMER AND DRILL Filed March 12. 1925 2 heets-Sheet 2 Patented July 26, 1927.

UNITED -A -p;s PATENT OFF 218621011133, SOUTH wmou'rn, MASSACHUSETTS.

- ELECTRIC lcE.

: mama.

Applicationflled men 12, 1925. Serial nausea.

This invention relates to improvements in electric hammersand drills and its main object is to provide an electric hammer having means incorporated therein for rotating the tool holder, thereby making it adaptable for drilling purposes and general millwright work.

, Another obj ectlis to provide in combination with the hammer a device for automatically regulating and controlling the electric current and wherein means are devised for short circuitin the current in case of an overload, and or breaking the short circuit when the excessive'load has been eliminated. These and other'golijects will be a parent from the accompanying drawings an specification. l In thedrawings: v a

Figureljis "top-plan" view of the hammer' Figure 2 fis" abottom plan view of the hammer;

Figure 3 is a ,longitudin'al section taken on the =line 3' -3? qt Figure 1';-' I Fi ure'Q4 i's'a l'on 'tudi'nal section taken on the 11119 H ofl ig m 3 Y incorporated therein to permit. securing the. I arts-of the cas'in g l l't'oge'ther by means of lts' asshownatii." The fieldljca sing 1 has casing 1 and ..Figu"'e'6'1s atransverse section taken on the line .of "Fi ure 3';

carryingfoutth'sflinvention provide a split insulated field basing having lugs 2 a series of grooves 4%cut therein in order to "ermit the mountin er. a field windin 5.

he said field-"win within'the y y gittdinallyiiin i the innerljfaceig oi. the field 5 are passed therethr'ough. A commutator bar 9 which carries'the field winding coil h l-ingsw r I of the coils which composeithe 'fieldwinding Figure 7, detailjof the current revers- 'in onta tsa igure='8,i's..a" diagram showing the travel bufferplate 11 is mounted. A coil s ring.

12 which serves the purpose of a shoe ab sorber for the piston 17 and is mounted upon the buffer late 11 is adapted to engage a disc 13 which is threadedly secured in the field casing 1. A steadying post 14, correspondin in cross-section to a quadrate cross, is passe through the casing and secured to the said disc 13. Conductors 15 and 16 are secured in and insulated against. the steadying post 14. A piston 17 having a quadrate aperture complementary to the steadving 0st 14, and which is adapted to travel the ength of the field winding 5-is slidlngly 1 is enlarged relative to the mounted upon the steadying post 14 and has a peripheral groove 18 cut therein in which a magnetic coil 19 is mounted. Brush cylinders 20 which have the ends of the coil 19 secured in the piston 17. Springs 21 and brushes 22 are mounted in the brush cylinders 20 and are adapted to engage the conductors 16' which are secured in the steadying post 14. A c Iinder 23 which is insulated a inst an secured in the piston 17 carries aiming 24 and brushes 25; the said brushes25 being adapted to engage the conductors 15 and the commutator bar 9. Contactstraps 26 and 27 and segments 28 and 29 are insulated against and secured to the upper inner face of the field casing 1. The

ends of the field winding 5 and the segments 128 are connected with suitable wiring 30,

-5 is held in .p acef means-of copper strips 6 'are-*" -in; dove-tail f coves -7..; rectangular: groove 8 which is lined withf'i'nsulating material is cut lonwhile suitable wiring 31 connects the conduc tor 15 with the segment 29, and suitable wiring 32' connects one of the conductors 16 with the contact strap 27, while the other conductor 16 is connected with the negative; 7 power line. Cam apertures 34 are cut in.

winding 5, wh le cams 35 arepassed therethrough and secured to 'ashaft 36 which is longitudinallv-journaled to the field casing the field casing 1 ateach end of the field 5 lot 1 by means of bearings 37. The cams135.

.have theirinner faces 38 cut at such an an-,

gle that their alternate engagement with the ends of the pistonl'! W111 cause the said cams 35 to traverse an anie of approximately 10 degrees. 7 A brus arm aperture 39 is cut in the up r portion of the field,

I in line wit thecam apertures 34. and a brusharm 40 is passed therethrough and to the shaft 36. Brush ning idle. .An end bearing 58 in which the th 7, incorporated therein.- The 41 and 42 carrying spring set brushes 43 and 44 respectively are insulated against and secured in the brush arm 40. The upper brush 43 of the finger 41 'engages the contact strap 26 while the lower brush 43 of the said finger 41 is adapted to alternately engage one of the segments 28 and the se ment 29, while the upper brush 44 of the ngtelr 42 engpges the contact strap 27 and t e lower rush 44 of the said ger, 42 alternately engages the segment 29 and one of the segments 28. It will be noted that when the south pole of the piston engages the lower pam 35, the brush arm 40 is shifted so that the brushes 43 of the' finger 41 engage the contact strap 26 and the segment 28, while the brushes 44 of the finger 42 enga e the contact strap 27 and the segment 29. n the north pole of the piston engages the u r cam 35, the arm 40 .is shifted so that e B nshee 43 of the finger 41 engage the contact strap 26 and the segment 29,'while the brushes 44 of the finger 42 engage the contact strap 27 and the segment 28. An insulated cap 45 carrying an end bearing. 46 in which 'the one end of the shaft 36 is journaled is secured to the to of the field casing 1. An end spacer 47 aving pawl apertures48 and 49 cut therein is threadedly secured to the lower end of the field casing 1.

'A spring set pawl 50 is mounted in the pawl a erture 48. An arm 51 which extends into t e awl aperture 49 and carries a spring set paw 52 is secured to the shaft 36. A tool holder 53 has ahead 54 which slidingly en-. gages the field casing 1 and theend spacer pawls 50 and 52 are adapted to engage ratchet teeth 55 which are cut in'the head 54 so that ever; time the north pole (N. P.) of the piston 1 tate a trifle. An end plate 56 canzmg' a bufier 57 is threadedly secured to t s end spgger 47. The said buffer 57 is provided toa rb the shock of the iston 17 when runlower end of the shaft 36 is journaled is secured to the end plate 56. A guard 59 is laced over the shaft 36 and secured to the eld casing 1 the cap 45 and the end plate 56. A hand'e plate 60 havingthe lower' half 63 of a switch 62 incorporated therein,

is secured to the cap 45. A spring set handle 61 having the upper half 64 of the switch 62 incorporated-wherein, is b y secured to the handle plate 60. The ower half 63 of the switch 62 isconnected with the contact strap 26 by means of suitable wiring 65,

while the upper half 64 is connected 'with suitable winn 66. I

' Reference inghad. mdre particularly -to the' di amm'atic Figure 8, the opera- I tion-is as: ollows: When the switch 62.;is

closed, the current-flows through the wiring 65 into the contact strap 26 whence it panes completing the circuit.

es the cam 35 the tool holder 53 is r0 upon the h and the other half from the bottom. From the segment 29 the current travels through the finger 42 and brushes 44 into the contact strap 27, through the contact strap 27 and the wiring 32 into one of the conductors 16, then throu b one of the brushes 22 into the coil 19 an then through the other brush 22 into the conductor 16 which is connected with the .negative power line 33, thus As shown in the diagrammatic Figure 8 ma etic fields of opposite polarity enter an leave the field winding 5 above andbelowthe piston during its reciprocation, and thus exert on-it simultaneously, a pushin and pulling force. When the piston 1 reaches the top of the field winding 5 it engages the upper cam 35 and causes the shaft 36 to be partially rotated to the right, thereb t e current to be reversed, at the same time moving the pawl into" 'tion for the parshifting the brush arm 40 and 1181118 connections are so ma e'the current p through the n tive line 33 into one of the conductors 16, rou h the brush '22 into the iston winding 19, en through the other rush 22 into the other conductor 16 and then throu h the wiring 82 into the contact strap 27. current passes through the brushes 44 and finger 42 into the segment 28, then ewiring30intothefieldwinding5,where the magnetic lines of force created by the field wmd' d 25 15 th t hrough th wlrmg con uc r an on e 31, the brushes 43 and finger 41 into the contact strap 26. When shi the lsn'lltihefl into the .'tion shown in a so that the iston 17 will be hurled down 54 of the tool holder 53. Just before the piston is hurled upon the tool holder it engages the-lower cam-35 and causes thesalnetopartiallyrotatetheshaft the'hrushrrm 40 into its former-position thecurrent for the up for-reversing ofthe'pisten.

magnetic hues of force are reversed 5 pass into the commutator I 1,eae,eaa I While I haveherein described a certain specific method of constructing and assembling the elements of myinvention, it is understood same may be varied in minor details, not departing from the spirit of my invention as defined in the appended claims.

1. In an electric hammer embodying a split field casing, 9. held winding in the easing, a wound reciprocating piston within the casing, a tool holderin the lower end of the casing, electric switches and reversing elements in said casing; a steadying post, corresponding to a quadrate cross in cross section, mounted longitudinally through the center of the casing, and upon which the said piston is slidingly mounted; means in the casing for absorbing the shock of the upward movement of the reciprocating piston; a tool holder adaptedto be engaged bythe piston in the lower portion of said casing; and means for rotating the tool holder thru the reciprocating movement of said piston.

2. In a device of the kind described, em:

bodying a split field casing, the said casing havin a commutator bar slot cut longitudi nally a ong its inner surface, a field winding in the casing, a wound piston within the casing, a tool holder at the lower endof the casing, and electric switches and reversing elements in said casing; a commutator bar mounted within the said slot of the casing,

as means for leading the current from the field winding of the casing through the switches into the piston winding; a shaft the casing wall in longitudinal alignment with the said brush arm aperture, one of-the said camapertures being located at the thru the reciprocating movement of said lower end of the casing and the other medially between,the lower cam and the said brush arm aperture; a shaft -journaled longitudinally at the outer face of the cats ing opposite the said cam and brush arm apertures; a brush arm mounted through the said brush arm aperture and connected to the shaft; reversing cams mounted through the cam apertures and connected to the shaft; brushes mounted at the inner end of and insulated against the said brusharm; se cuts and contacts mounted in and insu ated against the casing and adapted to cooperate with the said brushes for controlling the electric current.

4:. In a device as described in .claim 3 shock absorbing means in said casing for absorbing the 'power of the upward movement of the reciprocatin piston.

ture.

' NICHOLAS PISCIONERE.

In testimony whereo I afiix my signa- 

